Oxidation ovens are commonly used to produce carbon fibers from a precursor (such as an acrylic, pitch, or cellulose fibers). One common processing method involves successively drawing fibrous segments of the precursor material through one or more oxidation ovens.
Each of the oxidation ovens comprises a respective oxidation chamber in which the oxidation of the fiber segments takes place. Each fibrous segment can be drawn into a first oxidation oven at a first end as a carbon fiber precursor and then make multiple passes through each oxidation oven prior to exiting the final oxidation oven as an oxidized fiber segment. Roll stands and tensioners are used to draw the fibrous segments through the oxidation chambers of the ovens. Each oxidation oven heats the segments to a temperature approaching approximately 300° C. by means of a circulating flow of hot gas.
An example of such an oven is the Despatch Carbon Fiber Oxidation Oven, available from Despatch Industries, Minneapolis, Minnesota. A description of such an oven can be found in commonly-assigned U.S. Pat. No. 4,515,561. The oven described in the '561 Patent is a “center-to-ends” oxidation oven. In a center-to-ends oxidation oven, hot gas is supplied to the oxidation chamber of the oven from the center of the chamber and flows toward the ends of the chamber.
Typically, such a center-to-ends oxidation oven employs a single heating system to supply heated gas to the oxidation chamber of that oven. While some processing lines make use of multiple stacked oxidation ovens in a single processing line (where fiber exits one oven and enters the other oven), each of the stacked oxidation ovens uses a single heating system. That is, the heated gas supplied to the oxidation chamber of each stacked oven is supplied from a single heating system.